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jpgjs performance tuning

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fkaelberer 2014-02-18 09:24:59 -06:00 committed by Yury Delendik
parent 35f5a1ea5e
commit e874b272bf
1 changed files with 82 additions and 122 deletions
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204
external/jpgjs/jpg.js vendored
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@ -335,17 +335,16 @@ var JpegImage = (function jpegImage() {
var blocksPerLine = component.blocksPerLine; var blocksPerLine = component.blocksPerLine;
var blocksPerColumn = component.blocksPerColumn; var blocksPerColumn = component.blocksPerColumn;
var samplesPerLine = blocksPerLine << 3; var samplesPerLine = blocksPerLine << 3;
var R = new Int32Array(64), r = new Uint8Array(64); var R = new Int32Array(64);
// A port of poppler's IDCT method which in turn is taken from: // A port of poppler's IDCT method which in turn is taken from:
// Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz, // Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz,
// "Practical Fast 1-D DCT Algorithms with 11 Multiplications", // "Practical Fast 1-D DCT Algorithms with 11 Multiplications",
// IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989, // IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989,
// 988-991. // 988-991.
function quantizeAndInverse(zz, dataOut, dataIn) { function quantizeAndInverse(zz, p) {
var qt = component.quantizationTable; var qt = component.quantizationTable;
var v0, v1, v2, v3, v4, v5, v6, v7, t; var v0, v1, v2, v3, v4, v5, v6, v7, t;
var p = dataIn;
var i; var i;
// dequant // dequant
@ -429,7 +428,7 @@ var JpegImage = (function jpegImage() {
if (p[1*8 + col] == 0 && p[2*8 + col] == 0 && p[3*8 + col] == 0 && if (p[1*8 + col] == 0 && p[2*8 + col] == 0 && p[3*8 + col] == 0 &&
p[4*8 + col] == 0 && p[5*8 + col] == 0 && p[6*8 + col] == 0 && p[4*8 + col] == 0 && p[5*8 + col] == 0 && p[6*8 + col] == 0 &&
p[7*8 + col] == 0) { p[7*8 + col] == 0) {
t = (dctSqrt2 * dataIn[i+0] + 8192) >> 14; t = (dctSqrt2 * p[i+0] + 8192) >> 14;
p[0*8 + col] = t; p[0*8 + col] = t;
p[1*8 + col] = t; p[1*8 + col] = t;
p[2*8 + col] = t; p[2*8 + col] = t;
@ -492,8 +491,7 @@ var JpegImage = (function jpegImage() {
// convert to 8-bit integers // convert to 8-bit integers
for (i = 0; i < 64; ++i) { for (i = 0; i < 64; ++i) {
var sample = 128 + ((p[i] + 8) >> 4); p[i] = clampTo8bit((p[i] + 2056) >> 4);
dataOut[i] = sample < 0 ? 0 : sample > 0xFF ? 0xFF : sample;
} }
} }
@ -503,13 +501,13 @@ var JpegImage = (function jpegImage() {
for (i = 0; i < 8; i++) for (i = 0; i < 8; i++)
lines.push(new Uint8Array(samplesPerLine)); lines.push(new Uint8Array(samplesPerLine));
for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) { for (var blockCol = 0; blockCol < blocksPerLine; blockCol++) {
quantizeAndInverse(component.blocks[blockRow][blockCol], r, R); quantizeAndInverse(component.blocks[blockRow][blockCol], R);
var offset = 0, sample = blockCol << 3; var offset = 0, sample = blockCol << 3;
for (j = 0; j < 8; j++) { for (j = 0; j < 8; j++) {
var line = lines[scanLine + j]; var line = lines[scanLine + j];
for (i = 0; i < 8; i++) for (i = 0; i < 8; i++)
line[sample + i] = r[offset++]; line[sample + i] = R[offset++];
} }
} }
} }
@ -570,7 +568,7 @@ var JpegImage = (function jpegImage() {
for (var i = 0; i < blocksPerColumnForMcu; i++) { for (var i = 0; i < blocksPerColumnForMcu; i++) {
var row = []; var row = [];
for (var j = 0; j < blocksPerLineForMcu; j++) for (var j = 0; j < blocksPerLineForMcu; j++)
row.push(new Int32Array(64)); row.push(new Int16Array(64));
blocks.push(row); blocks.push(row);
} }
component.blocksPerLine = blocksPerLine; component.blocksPerLine = blocksPerLine;
@ -774,41 +772,35 @@ var JpegImage = (function jpegImage() {
getData: function getData(width, height) { getData: function getData(width, height) {
var scaleX = this.width / width, scaleY = this.height / height; var scaleX = this.width / width, scaleY = this.height / height;
var component1, component2, component3, component4; var component, componentLine, componentScaleX, componentScaleY;
var component1Line, component2Line, component3Line, component4Line; var x, y, i;
var x, y;
var offset = 0; var offset = 0;
var Y, Cb, Cr, K, C, M, Ye, R, G, B; var Y, Cb, Cr, K, C, M, Ye, R, G, B;
var colorTransform; var colorTransform;
var dataLength = width * height * this.components.length; var numComponents = this.components.length;
var dataLength = width * height * numComponents;
var data = new Uint8Array(dataLength); var data = new Uint8Array(dataLength);
switch (this.components.length) {
case 1:
component1 = this.components[0];
for (y = 0; y < height; y++) {
component1Line = component1.lines[0 | (y * component1.scaleY * scaleY)];
for (x = 0; x < width; x++) {
Y = component1Line[0 | (x * component1.scaleX * scaleX)];
data[offset++] = Y; // First construct image data ...
} for (i = 0; i < numComponents; i++) {
component = this.components[i];
componentScaleX = component.scaleX * scaleX;
componentScaleY = component.scaleY * scaleY;
offset = i;
for (y = 0; y < height; y++) {
componentLine = component.lines[0 | (y * componentScaleY)];
for (x = 0; x < width; x++) {
data[offset] = componentLine[0 | (x * componentScaleX)];
offset += numComponents;
} }
break; }
case 2: }
// PDF might compress two component data in custom colorspace
component1 = this.components[0]; // ... then transform colors, if necessary
component2 = this.components[1]; switch (numComponents) {
for (y = 0; y < height; y++) { case 1: case 2: break;
component1Line = component1.lines[0 | (y * component1.scaleY * scaleY)]; // no color conversion for one or two compoenents
component2Line = component2.lines[0 | (y * component2.scaleY * scaleY)];
for (x = 0; x < width; x++) {
Y = component1Line[0 | (x * component1.scaleX * scaleX)];
data[offset++] = Y;
Y = component2Line[0 | (x * component2.scaleX * scaleX)];
data[offset++] = Y;
}
}
break;
case 3: case 3:
// The default transform for three components is true // The default transform for three components is true
colorTransform = true; colorTransform = true;
@ -818,31 +810,19 @@ var JpegImage = (function jpegImage() {
else if (typeof this.colorTransform !== 'undefined') else if (typeof this.colorTransform !== 'undefined')
colorTransform = !!this.colorTransform; colorTransform = !!this.colorTransform;
component1 = this.components[0]; if (colorTransform) {
component2 = this.components[1]; for (i = 0; i < dataLength; i += numComponents) {
component3 = this.components[2]; Y = data[i ];
for (y = 0; y < height; y++) { Cb = data[i + 1];
component1Line = component1.lines[0 | (y * component1.scaleY * scaleY)]; Cr = data[i + 2];
component2Line = component2.lines[0 | (y * component2.scaleY * scaleY)];
component3Line = component3.lines[0 | (y * component3.scaleY * scaleY)];
for (x = 0; x < width; x++) {
if (!colorTransform) {
R = component1Line[0 | (x * component1.scaleX * scaleX)];
G = component2Line[0 | (x * component2.scaleX * scaleX)];
B = component3Line[0 | (x * component3.scaleX * scaleX)];
} else {
Y = component1Line[0 | (x * component1.scaleX * scaleX)];
Cb = component2Line[0 | (x * component2.scaleX * scaleX)];
Cr = component3Line[0 | (x * component3.scaleX * scaleX)];
R = clampTo8bit(Y + 1.402 * (Cr - 128)); R = clampTo8bit(Y + 1.402 * (Cr - 128));
G = clampTo8bit(Y - 0.3441363 * (Cb - 128) - 0.71413636 * (Cr - 128)); G = clampTo8bit(Y - 0.3441363 * (Cb - 128) - 0.71413636 * (Cr - 128));
B = clampTo8bit(Y + 1.772 * (Cb - 128)); B = clampTo8bit(Y + 1.772 * (Cb - 128));
}
data[offset++] = R; data[i ] = R;
data[offset++] = G; data[i + 1] = G;
data[offset++] = B; data[i + 2] = B;
} }
} }
break; break;
@ -855,35 +835,20 @@ var JpegImage = (function jpegImage() {
else if (typeof this.colorTransform !== 'undefined') else if (typeof this.colorTransform !== 'undefined')
colorTransform = !!this.colorTransform; colorTransform = !!this.colorTransform;
component1 = this.components[0]; if (colorTransform) {
component2 = this.components[1]; for (i = 0; i < dataLength; i += numComponents) {
component3 = this.components[2]; Y = data[i];
component4 = this.components[3]; Cb = data[i + 1];
for (y = 0; y < height; y++) { Cr = data[i + 2];
component1Line = component1.lines[0 | (y * component1.scaleY * scaleY)];
component2Line = component2.lines[0 | (y * component2.scaleY * scaleY)];
component3Line = component3.lines[0 | (y * component3.scaleY * scaleY)];
component4Line = component4.lines[0 | (y * component4.scaleY * scaleY)];
for (x = 0; x < width; x++) {
if (!colorTransform) {
C = component1Line[0 | (x * component1.scaleX * scaleX)];
M = component2Line[0 | (x * component2.scaleX * scaleX)];
Ye = component3Line[0 | (x * component3.scaleX * scaleX)];
K = component4Line[0 | (x * component4.scaleX * scaleX)];
} else {
Y = component1Line[0 | (x * component1.scaleX * scaleX)];
Cb = component2Line[0 | (x * component2.scaleX * scaleX)];
Cr = component3Line[0 | (x * component3.scaleX * scaleX)];
K = component4Line[0 | (x * component4.scaleX * scaleX)];
C = 255 - clampTo8bit(Y + 1.402 * (Cr - 128)); C = 255 - clampTo8bit(Y + 1.402 * (Cr - 128));
M = 255 - clampTo8bit(Y - 0.3441363 * (Cb - 128) - 0.71413636 * (Cr - 128)); M = 255 - clampTo8bit(Y - 0.3441363 * (Cb - 128) - 0.71413636 * (Cr - 128));
Ye = 255 - clampTo8bit(Y + 1.772 * (Cb - 128)); Ye = 255 - clampTo8bit(Y + 1.772 * (Cb - 128));
}
data[offset++] = C; data[i ] = C;
data[offset++] = M; data[i + 1] = M;
data[offset++] = Ye; data[i + 2] = Ye;
data[offset++] = K; // K is unchanged
} }
} }
break; break;
@ -894,54 +859,49 @@ var JpegImage = (function jpegImage() {
}, },
copyToImageData: function copyToImageData(imageData) { copyToImageData: function copyToImageData(imageData) {
var width = imageData.width, height = imageData.height; var width = imageData.width, height = imageData.height;
var imageDataBytes = width * height * 4;
var imageDataArray = imageData.data; var imageDataArray = imageData.data;
var data = this.getData(width, height); var data = this.getData(width, height);
var i = 0, j = 0, x, y; var i = 0, j = 0;
var Y, K, C, M, R, G, B; var Y, K, C, M, R, G, B;
switch (this.components.length) { switch (this.components.length) {
case 1: case 1:
for (y = 0; y < height; y++) { while (j < imageDataBytes) {
for (x = 0; x < width; x++) { Y = data[i++];
Y = data[i++];
imageDataArray[j++] = Y; imageDataArray[j++] = Y;
imageDataArray[j++] = Y; imageDataArray[j++] = Y;
imageDataArray[j++] = Y; imageDataArray[j++] = Y;
imageDataArray[j++] = 255; imageDataArray[j++] = 255;
}
} }
break; break;
case 3: case 3:
for (y = 0; y < height; y++) { while (j < imageDataBytes) {
for (x = 0; x < width; x++) { R = data[i++];
R = data[i++]; G = data[i++];
G = data[i++]; B = data[i++];
B = data[i++];
imageDataArray[j++] = R; imageDataArray[j++] = R;
imageDataArray[j++] = G; imageDataArray[j++] = G;
imageDataArray[j++] = B; imageDataArray[j++] = B;
imageDataArray[j++] = 255; imageDataArray[j++] = 255;
}
} }
break; break;
case 4: case 4:
for (y = 0; y < height; y++) { while (j < imageDataBytes) {
for (x = 0; x < width; x++) { C = data[i++];
C = data[i++]; M = data[i++];
M = data[i++]; Y = data[i++];
Y = data[i++]; K = data[i++];
K = data[i++];
R = 255 - clampTo8bit(C * (1 - K / 255) + K); R = 255 - clampTo8bit(C * (1 - K / 255) + K);
G = 255 - clampTo8bit(M * (1 - K / 255) + K); G = 255 - clampTo8bit(M * (1 - K / 255) + K);
B = 255 - clampTo8bit(Y * (1 - K / 255) + K); B = 255 - clampTo8bit(Y * (1 - K / 255) + K);
imageDataArray[j++] = R; imageDataArray[j++] = R;
imageDataArray[j++] = G; imageDataArray[j++] = G;
imageDataArray[j++] = B; imageDataArray[j++] = B;
imageDataArray[j++] = 255; imageDataArray[j++] = 255;
}
} }
break; break;
default: default: